Is it allowed to work for a company who develops softwares for Banks (involved in interest money)

Assalam-o-Alaikum An Important Question: I have been told by some muslims brothers that doing job for a Bank or a company which is involved in interest money is non-Islamic. Therefore muslims must not serve Banks specially. My Company I work for a company called City Networks Ltd. City Networks develops software for Banks. This software allows banks to match two confirmations automatically. The way Banks deals with one another is that they buy/sell money in various currencies. For example Barclays Bank buys 100k us dollars for 60k from Natwest. Now both banks create a confirmation in their computers which is eventually exchanged between them via network. City Networks software reads both confirmations and then match them automatically. My Job My job is to install this software on-site and make sure it is working ok. Q. Am I allowed to carry on with my job... according to Quran and Sunnah (please give references).